Currently, there are various products on the market that can heat water in a bath spa. Bath spas can be categorized into two types. The first type is designed to be laid on while taking a bath. These mat-style spas typically heat the bath water by pumping in warm air. This also allows the air jets to create massaging feeling for the user. While most mat-styled bath mats are capable of efficiently warming and circulating the bath water, many are ergonomically flawed due to their size which may not comply with certain tub dimensions, shape that is inconvenient for certain users, and materials that, when not padded sufficiently, is not comfortable of users to lay or sit on.
The second type of bath spa involves the use of a spa motor. These spas use jets to pump heated air bubbles into the water. One advantage of the portable jet bath spas is their size and cost; however, the jets do not circulate the water as well as most other bath spas. Certain larger, more expensive jet bath spas need to be installed into the side of a tub to function. In addition, these jet-powered bath spas are unable to warm the water.
Other similar devices include immersion circulators, which are used to cook food, aquarium heaters, which are used to support aquatic habitats, and standard household water heating tank.
Desirable in the art is an improved liquid heater that would improve upon the conventional liquid heater.